This project attempts to provide a theoretically sound and empirically grounded analysis of the "health system" of modern industrial society. The health system is defined as the aggregate of commitments and resources (human and material) any national society sets aside to deal with its health problems. Health is seen as a critical, natural and national resource the health system seeks to conserve, protect, and promote. The basic hypothesis is that the health system of industrial society undergoes a process of internal differentiation under the impact of certain universal factors such as increased effective demand for services and the growing availability of bio-medical technology. A further hypothesis is that the result of this process of differentiation will be a convergence of the health systems of industrial societies toward organizational and managerial patterns that will increasingly resemble each other in spite of different historical and cultural background. Such research may have, therefore, some gross predictive value as to the direction in which the American health system may develop. The approach followed here is (1) macrosociological; (2) evolutionary; (3) dynamic; (4) comparative; and (5) relevant. At the present the following national societies' health systems are being examined: United States, France, Japan, Soviet Union, Sweden, Norway, and England, and a typology of health systems has been devised.